Where FreeCAD Stores Temporary Files

During an active modeling session, FreeCAD extracts project data and writes working assets to the operating system's default temporary directory. Because FreeCAD's native .FCStd file format is essentially a zip archive containing XML metadata, brep shapes, and mesh files, the software unpacks these contents into a temporary session folder to enable fast read and write operations. This guide details where those active temporary files reside across Windows, Linux, and macOS, and how to identify the exact working directory within the software.

Default Temporary File Locations by Operating System

FreeCAD does not maintain a proprietary, isolated temporary folder by default; instead, it queries the host operating system for the designated temporary directory.

  • Windows: Temporary files are stored in the local user profile temp directory: C:\Users\<YourUsername>\AppData\Local\Temp You can quickly access this folder by pressing Win + R, typing %TEMP%, and pressing Enter. During a session, FreeCAD creates subfolders typically prefixed with FreeCAD or custom alphanumeric hashes.

  • Linux: On most Linux distributions, FreeCAD writes working files directly to: /tmp Some distributions or containerized builds (such as Flatpak or Snap) may direct temporary files to isolated locations:

    • Flatpak: ~/.var/app/org.freecad.FreeCAD/cache/tmp/
    • Snap: ~/snap/freecad/common/tmp/

  • macOS: macOS assigns randomized per-user temporary paths under the root variable directories: /var/folders/... You can locate your active temporary directory by opening Terminal and running echo $TMPDIR.

Finding the Active Session Path in FreeCAD

If you have a document open and need to find the exact folder containing its live shape definitions and XML files, use FreeCAD's built-in Python console:

  1. Open FreeCAD and ensure the Python console panel is visible (View > Panels > Python console).

  2. With an active document open, run the following command:

    App.ActiveDocument.TransientDir

  3. The console will print the absolute file path to the specific temporary directory assigned to that open document.

To find the general system temp directory FreeCAD is utilizing, run:

import tempfile
print(tempfile.gettempdir())

File Persistence and Cleanup Behavior

When FreeCAD closes normally, it automatically deletes these temporary directories and their unpacked contents to free disk space. However, if the application crashes or terminates unexpectedly, the temporary files remain on your disk.

FreeCAD uses these surviving temporary files alongside its auto-recovery files (which by default save every 15 minutes) to reconstruct unsaved work the next time you launch the application. If you are experiencing low disk space after multiple system crashes, you can safely delete stale FreeCAD temp folders from the OS temp directory as long as FreeCAD is not currently running.